Campton et al,: Genetic patchiness among Strombus gigas populations 



253 



Results 



Nineteen presumptive loci encoding 11 enzymes were 

 resolved electrophoretically (Table 2). Ten loci were 

 polymorphic and were used exclusively in the popula- 

 tion analyses (Table 3). 



Florida Keys and Bimini populations 



Allele frequencies for samples of queen conch from the 

 Florida Keys and Bimini were very similar (Table 3). 

 The gene identity between samples, averaged over the 

 ten polymorphic loci, ranged from 0.978 to 0.999 and 

 averaged 0.994 for all pairwise comparisons. Most 

 alleles were present in all samples, but some rare {P< 

 0.01) alleles were detected as only one or two hetero- 

 zygotes (e.g., AAT-1*130). An exception to this latter 

 generalization was the presence of the MDH-2* 138 



allele at a frequency of 0.206 (35 * 100/100, 11 * 100/138, 

 and 5 *138/138) among 51 scored individuals collected 

 from Ballast Key in 1987. Only one heterozygote for 

 this allele was observed elsewhere during the study. 



Genotypes conformed (P>0.05) to Hardy- Weinberg 

 proportions at all loci except DPEP-1 * . At this latter 

 locus, significant (P<0.01) deficits of heterozygotes 

 were detected in 7 of 10 samples. Overall, 285, 279, 

 and 244 individuals had the *100/100, *100/108, and 

 *108/108 genotypes, respectively, at DPEP-1*. This 

 overall deficit of heterozygotes occurred despite similar 

 (P>0.05) allele frequencies among samples (Table 3). 



Spatial and temporal variation in allele frequencies 

 accounted for minor but approximately equal amounts 

 of gene diversity. The total gene diversity (Hx) aver- 

 aged 0.202 for the ten polymorphic loci. Of this total, 

 0.60% and 0.50% were due to temporal and spatial 

 variation within and among localities, respectively 



